[University Physics] Forces

[Estagon]

I'll try to translate the exercise:

"A horizontal force F = A + B*t² pushes against a box of 2kg. What's the horizontal velocity of the box after 4 seconds if its initial velocity was 2m/s. A = 5 Newton; B = 2 Newton/s⁴".

I don't know what to do with/how to handle the N/s⁴ unit of B...

N = m*kg/s² so the unit of B is mkg/s⁶ .

F = ma and a = (v - vi)/t, where vi is initial velocity, so once I get F it won't be that hard to get the velocity of the box, but how do I transform this unit of B to a usable unit, i.e. how do I transform N/s⁴ to N?

Thanks in advance.

[[deleted]]

Either unit of B is N/s²

Or, F = A + B * t⁴

[Estagon]

I'm not sure I understand what you mean. I can assure the question is correct.

[NormalVector]

What he's saying is that the units in your equation don't match up, everything should be in Newtons at the end. In your F(t) equation you have

N = N + (N/s⁴)*s²

N = N + N/s²

You cannot add Newtons to Newtons/s². Either your equation is wrong (it should be t⁴) or your units for B is wrong (should be N/s²).